Develop a stiff jab and use it frequently. Also use your footwork to stay out of his range and to keep him at the end of your punches. Moving laterally with your feet will make it difficult for him to rush you. As your punches and footwork get sharper, I think this strategy could work very well for your build. It gets very frustrating fighting taller guys who pepper you with straight shots and run as soon as you try get in range!